This invention relates generally to the manufacture of electronic devices, including electronic displays, and particularly the encapsulation of such devices.
The encapsulation of electronic devices may involve the use of a viscous liquid material such a epoxy which is applied into voids and open areas within electronic devices. In some cases, the encapsulation prevents attack from contaminants such as water and air. In addition, encapsulation sometimes increases the structural integrity of the electronic device. For these and other reasons, it is often desirable to apply encapsulation material to electronic devices.
In a variety of circumstances, the area to be encapsulated may involve a relatively narrow region between surfaces of electronic devices. Examples of such situations are the encapsulation of an integrated circuit chip onto a printed circuit board and the encapsulation between panels in electronic display devices. In each case, a narrow, planar region must be encapsulated. However, the encapsulation material is generally somewhat viscous. Because of the intrusion of electronic devices into the encapsulation region or because of its narrowness, it may be difficult to provide an encapsulation source inwardly into the narrow region.
Given the narrowness of the encapsulation region, two problems may arise. Firstly, it may take an excessively long time to cause encapsulation to occur. With conventional techniques, beads of encapsulation are applied around the edges of the narrow region to be encapsulated. Capillary forces are then relied upon to draw the encapsulant inwardly into the encapsulated region. In some cases, the encapsulation material is only applied on two of four edges. One reason for doing so is to attempt to avoid creating air pockets within the encapsulated region due to the intersection of fronts of ongoing, moving encapsulation material, drawn by capillary forces. Thus, the amount of time involved in encapsulating relatively large areas may be excessive.
Secondly, it may be difficult to cause the encapsulation to occur within the remote region defined by narrow surfaces without creating air pockets within the region. The air pockets can cause the very problems that encapsulation was intended to overcome. Namely, air pockets may facilitate attack by external contaminants and reduce structural integrity of the encapsulated product.
Thus, there is a need for better ways to encapsulate electronic devices.